The present invention refers to a process and an arrangement for producing blow-molded hollow bodies from plastic by means of a blow-molding machine, wherein preferably a gaseous cooling medium can be blown into the blow mold or into the hollow body for blowing the hollow body and cooling the blow-molded body via a conduit. After blowing the hose shaped pre-form made of moldable plastic material into the actual hollow body, the final blow-molded hollow body or the plastic product must subsequently remain in the mold and cooled until it has reached a sufficient inherent stability and can then be taken from the mold. The time in which the hollow body is cooled is defined as the cooling period.
The cooling procedure of the plastic hollow body in the blow mold is generally the slowest and is thus the time-determinative step in the productivity of a blow molding machine. When reducing the cooling period, the efficiency or the number of discharged pieces of the article produced per time unit can be raised considerably. Cooling of the hollow body within the blow mold is carried out on the one hand from the outside through a direct contact of the plastic material with the interior wall of the cooled blow form and on the other hand, from the inside via the cooling medium which is blown in. According to the prior art, cooling is understood to mean all methods where heat is withdrawn from the inner wall of the blow molding piece. Thereby, a heat transfer takes place from the inner side of the surface of the hollow body to the cooling media that are within the hollow body and a subsequent heat transport away therefrom. The energy which is taken up through the media is taken from the hollow body and together with the media is dissipated to the outer environment.